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1.
本文通过对中国沿海25个观测站水位资料的分析,初步探讨了中国沿海1980-2012年增减水的变化特征及与海平面变化的关系。结果表明:（1）中国沿海增减水的季节变化特征明显,相邻站由于受到的气象状况相同,其沿海增减水变化的过程相近,但是变化幅度存在较大差异。从空间分布看,沿海增减水的变化幅度呈现中间大南北小的区域特征,自长江口至广东沿海,增减水的年变化幅度最大,年变幅平均为5.0~7.5 cm;南海周边及北部湾沿海,增减水的年变化幅度次之,年变幅平均为4.0~5.5 cm;自渤海至黄海沿海,增减水的年变化幅度较小,年变幅平均为3.3~3.5 cm。（2）从时间变化看,1980-2012年中国沿海年平均增减水长期基本没有趋势性变化,但明显存在2至5年的周期性变化信号,该信号的震荡幅度为0.1 cm。经过高频滤波后,对沿海月平均增减水序列与Niño3.4指数进行相关性分析,相关系数为-0.5,该相关系数通过了显著性检验,说明中国沿海的增减水变化与ENSO事件呈现负相关关系。（3）中国沿海增减水的长期变化及空间分布特征均与海平面变化不同。1980-2012年,中国沿海海平面的上升速率为2.9 mm/a,而增减水长期基本无趋势性变化;另外,其季节变化与海平面的季节变化从时间和区域上均不存在一致性。（4）但是,短期海平面的变化与增减水有关,并且增减水对短期海平面的贡献根据其具体情况而定,增水幅度大且持续时间长的过程对短期海平面有抬升作用,其贡献率最大可达65%;反之,减水幅度大且持续时间长的过程则对短期海平面有降低的作用。 相似文献
2.
基于海洋站潮位观测和中国沿海海平面变化影响调查等数据,分析了辽东湾沿岸海平面变化及海岸侵蚀状况,并定量评估了未来海平面上升情景下,辽东湾两岸典型沙质海岸侵蚀影响和沙滩养护投入。分析预测和评估结果表明:1980-2017年,辽东湾沿海海平面上升速率为3.0 mm/a,其中辽东湾东岸沿海海平面上升速率明显高于西岸。2009-2017年,辽宁营口白沙湾、绥中网户、绥中南山港和绥中团山气象观测场岸段后退和下蚀较为严重,部分岸段滩肩蚀退达2～3 m/a。预计2100年,辽东湾沿海海平面上升幅度在20～48 cm之间,由海平面上升引发的辽东湾海岸侵蚀土地损失为23.1 km2,土地经济损失为1410万元。为减缓海岸侵蚀,旅游沙滩和一般沙滩养护总投入分别为11亿元和46亿元,全岸段养护成本较高,应选取旅游沙滩等重点岸段进行养护。 相似文献
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2012年中国沿海海平面上升显著成因分析 总被引：3，自引：0，他引：3
2012年,中国沿海海平面变化最突出的特点是海平面升高显著。海平面总体比常年高122mm,较2011年偏高53mm,达1980年以来最高位。本文使用中国沿海及西北太平洋区域近30a的水位、海温、气温、气压和风等水文气象资料,详细分析了中国沿海海平面2012年异常偏高的成因。结果表明:2010-2012年中国沿海海平面处于2~3a、8~9a和准19a周期震荡的高位,几个周期震荡高位叠加,对海平面上升起了明显的影响;2012年,沿海气温和海温分别较常年偏高0.4℃和0.3℃,气压较常年低1.2hPa,气压达历史最低位;2012年,中国南海夏季风爆发时间较常年偏早,结束较常年偏晚,季风持续时间较常年偏长,导致2012年5-6月和8月,在黄海和东海海域,东北风持续偏强,南海海域南风偏强,风场的异常导致黄海、东海和南海沿海海水长时间堆积,是造成海平面升高的原因之一;2012年,热带气旋登陆时间集中,影响范围广,北上和影响东北地区的台风数量均为历史之最,特别是2012年8月,有6个热带气旋相继影响我国沿海,对当月海平面升高影响明显;另外,2012年副热带高压偏北、偏东、偏弱的特点对东海和南海的海平面上升也有一定影响。 相似文献
5.
海平面上升对中国沿海地区影响初析 总被引：2，自引：0，他引：2
近五十年来中国沿岸海平面变化总的呈上升趋势，年变率平均为１．４ｍｍ／ａ，中国沿岸地形复杂，未来海平面上升可能影响的主要脆弱区为黄河、长江和珠江三大三角洲和滨海平原，其可能受害区域估计达３５０００ｋｍ＾２。影响中国沿岸相对海平面上升的主要因素有：近代地壳垂直运动和地面沉降，台风和风暴潮，海岸侵蚀和海咸水入侵等。 相似文献
6.
南海北部沿岸冬季水位亚潮波动特征研究 总被引：1，自引：0，他引：1
用时间序列分析方法研究了南海北部水位亚潮波动的基本特征。结果表明南海北部冬季水位亚潮波动能量以福建南部沿岸最强,广东沿岸仅为台湾海峡南部的一半左右,但二者具有相似的谱特征。各站的功率谱峰均出现在3.2,6.4,3.6和2.3d频带。其中3.2和6.4d波动能量最强。此外,在珠江口附近还有10.7d的较弱谱峰。与东海沿岸冬季情况类似,南海北部沿岸水位波动有很高的空间相关性,说明冬季我国东南沿海的亚潮波动受某一共同机制的控制。分析还表明水位波动一致地从东北向西南传播,但在不同岸段传播特征有相当差异。 相似文献
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区域海平面变化是目前气候变化研究的热点问题。海平面变化具有时间和空间的异质性,分析海平面变化,应充分考虑时间和空间的差异。基于集合经验模态分解(Ensemble Empirical Mode Decomposition,EEMD)、最小二乘法,利用卫星高度计、验潮站数据,分析了1993—2016年间中国近海及周边海域海平面的时空变化规律。利用EEMD,计算了1993—2016年中国近海海平面变化空间结构的时间变化规律。结果表明中国近海海平面持续升高,但海平面变化在空间分布和时间上的变化并不均匀。空间结构大致分三个部分:大陆沿岸海平面持续上升且上升速率逐年增加,近海海区升高速率逐年降低,而研究区域内的西太平洋西部海区先减速升高又加速降低。分别利用EEMD分解和线性最小二乘拟合算法计算了1993—2016年中国近海海平面平均上升速率的空间分布,结果表明两种方法得到的海平面升高速率的空间分布大致吻合。两种方法均显示沿海地区的上升速率远大于近海海区,沿海地区上升速率大约为6 mm/a,近海海区上升速率大约为2 mm/a。但EEMD方法显示在广东沿岸和靠近赤道部分区域的上升速率更大。分别计算了大陆沿岸、近海及西太平洋西部海区三个海区内空间平均的海平面时间变化的线性及非线性趋势。非线性趋势显示大陆沿岸海区海平面加速上升,上升速率由1993年的3.65 mm/a,增加到2016年的5.03 mm/a;近海地区海平面上升速率逐年变小,由1993年的4.51 mm/a,减缓至2016年的3.8 mm/a;西太平洋西部海区海平面先减速上升,后加速下降,从1993年的上升率为9.5 mm/a,逐渐变化到2016年的下降率为2.27 mm/a。利用验潮站数据分析了大连、坎门、香港的水位变化,除大连海平面上升速率降低外,其余均显示海平面上升速度逐年升高,和卫星高度计的结果吻合。 相似文献
8.
Tariq Masood Ali Khan D. A. Razzaq Qamar-Uz-Zaman Chaudhry Dewan Abdul Quadir Anwarul Kabir Majajul Alam Sarker 《Marine Geodesy》2002,25(1):159-174
The UNEP in its regional seas program in 1989 has included Pakistan in a group of countries which are vulnerable to the impact of rising sea level. If the present trend of sea level rise (SLR) at Karachi continues, in the next 50 years the sea level rise along the Pakistan Coast will be 50 mm (5 cm). Since the rising rates of sea level at Karachi are within the global range of 1-2 mm/year, the trends may be treated as eustatic SLR. Historical air temperature and sea surface temperature (SST) data of Karachi also show an increasing pattern and an increasing trend of about 0.67°C has been registered in the air temperature over the last 35 years, whereas the mean SST in the coastal waters of Karachi has also registered an increasing trend of about 0.3°C in a decade. Sindh coastal zone is more vulnerable to sea level rise than Baluchistan coast, as uplifting of the coast by about 1-2 mm/year due to subduction of Indian Ocean plate is a characteristic of Baluchistan coast. Within the Indus deltaic creek system, the area nearby Karachi is more vulnerable to coastal erosion and accretion than the other deltaic region, mainly due to human activities together with natural phenomena such as wave action, strong tidal currents, and rise in sea level. Therefore, The present article deals mainly with the study of dynamical processes such as erosion and accretion associated with sea level variations along the Karachi coast and surrounding Indus deltaic coastline. The probable beach erosion in a decade along the sandy beaches of Karachi has been estimated. The estimates show that 1.1 mm/year rise in sea level causes a horizontal beach loss of 110 mm per year. Therefore, coast eroded with rise in sea level at Karachi and surrounding sandy beaches would be 1.1 m during a period of next 10 years. The northwestern part of Indus delta, especially the Gizri and Phitti creeks and surrounding islands, are most unstable. Historical satellite images are used to analyze the complex pattern of sediment movements, the change in shape of coastline, and associated erosion and accretion patterns in Bundal and Buddo Islands. The significant changes in land erosion and accretion areas at Bundal and Buddo Islands are evident and appear prominently in the images. A very high rate of accretion of sediments in the northwestern part of Buddo Island has been noticed. In the southwest monsoon season the wave breaking direction in both these islands is such that the movement of littoral drift is towards west. Erosion is also taking place in the northeastern and southern part of Bundal Island. The erosion in the south is probably due to strong wave activities and in the northeast is due to strong tidal currents and seawater intrusion. Accretion takes place at the northwest and western parts of Bundal Island. By using the slope of Indus delta, sea encroachment and the land area inundation with rising sea level of 1 m and 2 m have also been estimated. 相似文献
9.
Tariq Masood Ali Khan D. A. Razzaq Qamar-Uz-Zaman Chaudhry Dewan Abdul Quadir Anwarul Kabir Majajul Alam Sarker 《Marine Geodesy》2013,36(1-2):159-174
The UNEP in its regional seas program in 1989 has included Pakistan in a group of countries which are vulnerable to the impact of rising sea level. If the present trend of sea level rise (SLR) at Karachi continues, in the next 50 years the sea level rise along the Pakistan Coast will be 50 mm (5 cm). Since the rising rates of sea level at Karachi are within the global range of 1-2 mm/year, the trends may be treated as eustatic SLR. Historical air temperature and sea surface temperature (SST) data of Karachi also show an increasing pattern and an increasing trend of about 0.67°C has been registered in the air temperature over the last 35 years, whereas the mean SST in the coastal waters of Karachi has also registered an increasing trend of about 0.3°C in a decade. Sindh coastal zone is more vulnerable to sea level rise than Baluchistan coast, as uplifting of the coast by about 1-2 mm/year due to subduction of Indian Ocean plate is a characteristic of Baluchistan coast. Within the Indus deltaic creek system, the area nearby Karachi is more vulnerable to coastal erosion and accretion than the other deltaic region, mainly due to human activities together with natural phenomena such as wave action, strong tidal currents, and rise in sea level. Therefore, The present article deals mainly with the study of dynamical processes such as erosion and accretion associated with sea level variations along the Karachi coast and surrounding Indus deltaic coastline. The probable beach erosion in a decade along the sandy beaches of Karachi has been estimated. The estimates show that 1.1 mm/year rise in sea level causes a horizontal beach loss of 110 mm per year. Therefore, coast eroded with rise in sea level at Karachi and surrounding sandy beaches would be 1.1 m during a period of next 10 years. The northwestern part of Indus delta, especially the Gizri and Phitti creeks and surrounding islands, are most unstable. Historical satellite images are used to analyze the complex pattern of sediment movements, the change in shape of coastline, and associated erosion and accretion patterns in Bundal and Buddo Islands. The significant changes in land erosion and accretion areas at Bundal and Buddo Islands are evident and appear prominently in the images. A very high rate of accretion of sediments in the northwestern part of Buddo Island has been noticed. In the southwest monsoon season the wave breaking direction in both these islands is such that the movement of littoral drift is towards west. Erosion is also taking place in the northeastern and southern part of Bundal Island. The erosion in the south is probably due to strong wave activities and in the northeast is due to strong tidal currents and seawater intrusion. Accretion takes place at the northwest and western parts of Bundal Island. By using the slope of Indus delta, sea encroachment and the land area inundation with rising sea level of 1 m and 2 m have also been estimated. 相似文献
10.
This paper describes changes in sea level off the coast of China in history and at present. The evidence concerning low sea
level during the last glacial phase, Holocene marine transgression which was discovered from sea bottom in East China Sea
and China's bordering seas, and their adjacent coastal areas, where, by drilling, relic sediment, peat deposite, and mollusc
shell fossils have been obtained, and their dates are deduced through measurement of radiocarbon (C14), identified that low sea level about 15000 years ago stood in the depth of 150 m below the present level in East China Sea,
and that the subsequent transgression carried the sea up to the present sea level 6000 years ago, when the present China's
coast and other continent's coasts were outlined.
Due to a number of factors, the sea level oscillates seasonally in the border sea of China. Averagely speaking, the annual
range of the seasonal changes in sea level is about 35 m off the south Zhejiang coast, where the highest value of 20 cm occurs
in September, and the lowest of-15 cm occurs in March. The reason may be mainly due to the seasonal variations of climate
and river run-off, as well as the Taiwan Warm Current. Similar seasonal oscillations in sea level also occur in Bohai Gulf,
Yellow Sea, East China Sea and the South China Sea.
The beach process of south Zhejiang is strongly affected by the seasonal oscillations in sea level. The width of beach is
4 to 6 km, the slope is approximately in 1 : 1000. If the sea level rises or falls 1 cm, the beach submergence or emergence
is led to be about 10 m in width. As a result, the relative equilibrium of beach will be changed by the seasonal oscillations
in sea level. 相似文献
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南海沿海季节性海平面异常变化特征及成因分析 总被引：1，自引：1，他引：0
Based on sea level, air temperature, sea surface temperature(SST), air pressure and wind data during 1980–2014,this paper uses Morlet wavelet transform, Estuarine Coastal Ocean Model(ECOM) and so on to investigate the characteristics and possible causes of seasonal sea level anomalies along the South China Sea(SCS) coast. The research results show that:(1) Seasonal sea level anomalies often occur from January to February and from June to October. The frequency of sea level anomalies is the most in August, showing a growing trend in recent years. In addition, the occurring frequency of negative sea level anomaly accounts for 50% of the total abnormal number.(2) The seasonal sea level anomalies are closely related to ENSO events. The negative anomalies always occurred during the El Ni?o events, while the positive anomalies occurred during the La Ni?a(late El Ni?o) events. In addition, the seasonal sea level oscillation periods of 4–7 a associated with ENSO are the strongest in winter, with the amplitude over 2 cm.(3) Abnormal wind is an important factor to affect the seasonal sea level anomalies in the coastal region of the SCS. Wind-driven sea level height(SSH) is basically consistent with the seasonal sea level anomalies. Moreover, the influence of the tropical cyclone in the coastal region of the SCS is concentrated in summer and autumn, contributing to the seasonal sea level anomalies.(4) Seasonal variations of sea level, SST and air temperature are basically consistent along the coast of the SCS, but the seasonal sea level anomalies have no much correlation with the SST and air temperature. 相似文献
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东海沿海季节性海平面异常成因 总被引：1，自引：0，他引：1
Based on the analysis of sea level, air temperature, sea surface temperature(SST), air pressure and wind data during 1980–2013, the causes of seasonal sea level anomalies in the coastal region of the East China Sea(ECS) are investigated. The research results show:(1) sea level along the coastal region of the ECS takes on strong seasonal variation. The annual range is 30–45 cm, larger in the north than in the south. From north to south, the phase of sea level changes from 140° to 231°, with a difference of nearly 3 months.(2) Monthly mean sea level(MSL)anomalies often occur from August to next February along the coast region of the ECS. The number of sea level anomalies is at most from January to February and from August to October, showing a growing trend in recent years.(3) Anomalous wind field is an important factor to affect the sea level variation in the coastal region of the ECS. Monthly MSL anomaly is closely related to wind field anomaly and air pressure field anomaly. Wind-driven current is essentially consistent with sea surface height. In August 2012, the sea surface heights at the coastal stations driven by wind field have contributed 50%–80% of MSL anomalies.(4) The annual variations for sea level,SST and air temperature along the coastal region of the ECS are mainly caused by solar radiation with a period of12 months. But the correlation coefficients of sea level anomalies with SST anomalies and air temperature anomalies are all less than 0.1.(5) Seasonal sea level variations contain the long-term trends and all kinds of periodic changes. Sea level oscillations vary in different seasons in the coastal region of the ECS. In winter and spring, the oscillation of 4–7 a related to El Ni?o is stronger and its amplitude exceeds 2 cm. In summer and autumn, the oscillations of 2–3 a and quasi 9 a are most significant, and their amplitudes also exceed 2 cm. The height of sea level is lifted up when the different oscillations superposed. On the other hand, the height of sea level is fallen down. 相似文献
13.
Dongju Peng Hindumathi Palanisamy Anny Cazenave Benoit Meyssignac 《Marine Geodesy》2013,36(2):164-182
Spatial patterns of interannual sea level variations in the South China Sea (SCS) are investigated by analyzing an EOF-based 2-dimensional past sea level reconstruction from 1950 to 2009 and satellite altimetry data from 1993 to 2009. Long-term tide gauge records from 14 selected stations in this region are also used to assess the quality of reconstructed sea levels and determine the rate of sea level along the coastal area. We found that the rising rate of sea levels derived from merged satellite altimetry data during 1993–2009 and past sea level reconstruction over 1950–2009 is about 3.9 ± 0.6 mm/yr and 1.7 ± 0.1 mm/yr, respectively. For the longer period, this rate is not significantly different from the global mean rate (of 1.8 ± 0.3 mm/yr). The interannual mean sea level of the SCS region appears highly correlated with Niño 4 indices (a proxy of El Niño-Southern Oscillation/ENSO), suggesting that the interannual sea level variations over the SCS region is driven by ENSO events. Interpolation of the reconstructed sea level data for 1950–2009 at sites where tide gauge records are of poor quality (either short or gapped) show that sea level along the Chinese coastal area is rising faster than the global mean rate of 1.8 mm/yr. At some sites, the rate is up to 2.5 mm/yr. 相似文献
14.
Response of the low-frequency fluctuations of sea level to atmospheric forcing along the coasts of the Huanghai Sea and the East China Sea 总被引：1，自引：0，他引：1
In this paper, the low-frequency fluctuations of sea level and their relationship to atmospheric forcing along the coasts of the Huanghai Sea and the East China Sea are studied. Spectrum analyses are made for the time series of daily mean sea level, atmospheric pressure and wind stress at seven coastal stations. It is found that at all the stations, the main part of the energy of the sea level fluctuations, within the (2-60)-day period, is concentrated on the (12-60)-day period band and that an obvious spectral peak appears at the 3-day period. Along the coast of the Huanghai Sea, variations in the sea level are greater in winter than in summer. In winter, along the coasts of the Huanghai Sea and the East China Sea there is a kind of sea level fluctuations propagating southwards. Among the many factors causing sea level variation, the most obvious one is atmospheric pressure, followed next by the alongshore wind stress. 相似文献
15.
渤黄海沿海2月份海平面异常偏高成因分析 总被引：5，自引：0，他引：5
使用1980—2010年的水位、气温、海温、气压和风场资料,对中国渤黄海沿海2月份的海平面变化特征以及异常偏高成因进行了探讨,分析结果表明:近30年,渤黄海沿海2月份海平面呈现明显的上升趋势,2009年和2010年2月份的海平面达到近30年的高值,冬季高海平面导致全年平均海平面偏高。近两年2月份海平面处于多个长周期振动的高位重合期,各振幅叠加的结果近100 mm,对海平面起了明显的抬升作用。高海平面使得辽宁、河北以及山东等沿岸地区的海水入侵距离和土壤盐渍化程度均有所增加,海岸侵蚀加重;上海在2009—2010年连续2年2月份发生了近年较严重的咸潮入侵。2009年和2010年2月份,气压较常年同期显著偏低,冬季季风显著偏弱,是海平面上升的主要原因之一。 相似文献
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17.
中国近海海平面变化研究进展 总被引：7，自引：0，他引：7
通过对近10年来中国近海海平面变化研究成果的分析得出:(1)中国海域海平面变化时空差异明显,沿海海平面高值出现在8—9月,最低值出现在2—3月,季节最大差值可达20.75 cm;黄海和东海海区东南高、西北低;南海夏季西低东高,冬季东低西高;从辽宁到广西海平面上升速率差异大,范围在-2.1~10 mm/a之间;相对海平面上升较快区域主要是黄河三角洲、长江三角洲和珠江三角洲,2050年3个地区海平面预计分别上升980、720、520 mm。(2)地面沉降已经成为中国东部沿海相对海平面上升速率高的重要影响因素,在黄河三角洲和长江三角洲人口密集地区尤为突出。(3)每年8—9月为我国一年中的海平面最高月份,此时也正是热带气旋影响中国东南沿海的高峰时段,在季风、热带气旋等共同作用下,东南沿海高海平面将对东南沿海城市安全构成严重威胁。 相似文献
18.
本文对浙江沿岸海平面变化研究中的若干问题进行了分析和讨论,结果表明:浙江沿岸海面形状较平坦。海平面变化呈上升趋势,在过去的30～33年间,用长涂、镇海和坎门站长期潮位资料分析,海平面年上升速率为2.3mm/a。预测今后几十年间浙江沿岸海平面处在一个上升时期。 相似文献
19.
Winter appearance of a northeastward warm current off the southern coast of China against gale force winds is well documented but lacks a plausible explanation. Relaxation of northeasterly winds is envisaged here as a possible cause of the South China Sea Warm Current in winter. A three-dimensional circulation model for the South China Sea is first driven to equilibrium by climatological forcings. Thereafter, wind forcing is relaxed from the 15th day of each month for 9 days. In winterlike months from December to April, the wind relaxation invariably triggers a northeastward current of which the location and alongshore span are comparable to that of the observed warm current. This current is driven by the pressure gradient along the northwestern boundary of the South China Sea, sea level being high to the southwest and low to the northeast. The sea level gradient is built up by the monsoon-driven southwestward coastal current along the northwestern boundary and, after wind relaxes, triggers a return current and a sea level drop that expand southwestward from the southern coast of China to the east coast of Vietnam. The current is initially barotropic, becoming increasingly baroclinic in time as warm waters from the south are advected northeastward. The model also suggests that the sea level gradient is present in most of the months of the year, but is not as dramatic as in winter to trigger fundamental changes in the circulation of the South China Sea. 相似文献
20.
我国海岸带主要灾害地质因素及其影响 总被引：13，自引：2，他引：13
我国海岸带灾害地质主要有构造、坡地重力、水动力、地下水、岩土与地层结构、海平面上升、地球化学、风力灾害等地质因素，具有复杂、连锁和差异性空间分布的特征。根据验潮资料，近百年来我国海平面上升19～20cm，上升率为2～3mm／a。整体以海平面上升为主，但也有岸段下降，主要是山东半岛，平均速率为-0．13cm／a。预测2050年上升幅度：天津70～100cm；黄河三角洲40～50cm；长江三角洲50～70cm；珠江三角洲40～60cm。地面沉降大部分是由过量开采地下水引起的。我国96个地面沉降城市和地区中80％在沿海地区，如天津、上海、苏州、常州、无锡、嘉兴、宁波、湛江、台北等。累计沉降量为460～2780mm，沉降速率10～56mm／a。由于地下水的过量开采，20世纪80年代以来，我国辽宁、河北、天津、山东、江苏、上海、广西、海南和台湾等省市，均发生不同程度的海水入侵，给国民经济和社会发展造成重大损失。我国70％砂质海岸和大部分淤泥质海岸发生侵蚀。这种态势始于上世纪50年代，80年代明显加强。海岸侵蚀主要有区域环境变化、河流水利工程拦截泥沙以及海岸人工采沙等因素。 相似文献